Liz from YouTube support posted a notification about the issue. She said:
We're seeing many of you reporting that you're having trouble with uploads- your uploads are not processing completely and are getting stuck before going to live.
Our team is aware of the issue and has a fix in the works. Uploads should return to normal soon.
In the meantime, please be aware that trying to re-upload your video will not resolve the situation. Your original upload will go through and complete processing, its just somewhat delayed and will take longer than usual to go live (as you've noticed).
We appreciate your understanding, and as always, thank you all for your reports alerting us of this situation.
So, upload the video as you would, but don't worry, the videos will be published eventually. There is no need to reupload your videos.